Telephonic repeater



(No Model.)

' T. A EDISON. TBLEPHONIG REPEATER Patented Ap rp27, 1886.

INVENT OR chat UNITED STATES PATENT OFFICE.

THOMAS A.1EDISON, or MENLO PARK, NEW JERSEY.

TELEPHONIC nape/wen.

SPECIFICATION forming part of Letters Patent No. 340,707, dated April27, 1886.

Application filod December 15, 1884. Serinl'NoI 150,347. (No model.)

To all whom 'it may concern;

Be it known that I, THOMAS A: EDISON, of Mcnlo Park, in the county ofMiddlesex and State of New Jersey, have invented anew and (Case No.639;) specification.

The object I have in view is to produce -a telephone-repeater forrelaying telephone un-. dnlations from either of two lines to the other,which will operate without the use of switches for changing the line andlocal circuits in the relay apparatus, and will at the same time produceclear articulation free from the con.-

1 fusion produced by the reciprocal action of the repeating-instruments.4

A further object is to produce an'arrangement whereby a single combinedreceiver and transmitter can be-used to relay in eitherdirection'n'ithont the use ofswitch'ingapparatus,

and also to provide means whereby my'devices for relaying in eitherdirection without switches can be used effectively with connected linesof widely-diflerent resistances.

The invcntion'will bebetter understood by reference to the accompanyingdrawings, in whichhignre 1 is a view principally in dia-- gram'of atelephone repeater embodying my invention, and Fig. 2 a view in detailof the receiving induction-coil.

of which the" following is'aduction-coil O. The induction-circuits 1 and2 are formed of wire wound together upon the core, the lines A B beingconnected'at opposite ends of the core to the two circuits,so astoopposeeach other in their inductive action. The other ends of theinduction-circuitsl 2 are connected together and through thesecondary40, of induction-coil D to earth. The inductioncoil 0 has a thirdcircuit, 3, in which is located the receiver E. This is anelectro-motograph receiver, the chalk-cylinder of which is kept rotatingconstantly by any suitable means. 5 F is a telephone-transniitter of anysuitable construction. Its case is connected with the receiver-case byachannel,-a, with closed walls. The transmitter is in circuit withprimary-oi D and with a battery, G. I

In speaking over either line the current-un- 'o dulatious will passthrough 1 or 2Tof C, and to useful Improvement in Telephone-Repeaters,-

A and B are two telephone-lines, which are connected with difi'ercntcircuits 1 2 of the inearththrough' secondary of D, thengreaterresistance of the other line preventing any action 'in the other circuit(2 or 1) 01' 0. The electro-motograph receiver will be operated by in-51 duction,and will throw sound-waves through channel a ohto thetransmitter-diaphragm. The transmitter acting through primary of D theinduced undulations in secondary of D will pass out through both 1 and 2of 0 upon both lines. The induction in C will be neutralized, and thereaction upon the receiver prevented.

For working connected lines of widely-differe'nt resistances adjustableresistances Band 6 R are used for balancing the lines, which resistancesare located in shunts around coils 1 and 2 of inductioncoil C. Byadjusting these resistances the action of the induction in the coils land. 2 can be made equal, so that the inductive action fromrepeating-coil \D will be neutralized in receiving-coil C.

What I claim is-' 1.. In a telephone-repeater, the combination, with twotelephone-lines, of a receiving in- 73 dnction-eoil having twoopposingprimary circuits and a repeating induction-coil whose secondarycircuit is connected with both the primary circuits of the receivinginductioncoil, substantially as set forth.

- 2. In atelephone-repeater, the combination, with two telephone-lines,of a receiving induction-coil having two opposing primary circuits,a'repeating induction-coil whose secondary is in circuit with both saidprimary circuits',and a repeating telephone-receiver operated byinduction from the receiving induction coil, substantially as set forth.

3. 'In atelephone-repeat'er, the combination, with two telophone-lines,'of arec'eiving'induction-coil having two opposing primary circuitsconnected with said lines, a repeatin telephone-receiver in thesecondary circuito .such

receiving-coil, a transmitting induction-coil having its secondary incircuit with the opposmg circuits of the receiving. induction-coil, anda repeating telephone-transmitter worked by. the receiver and located inthe primary circuit of the repeating induction-coil, substantially asset forth.

4. In a telephone-repeater, the combination, with two telephone-lines,-of a receiving induc- Mon-c011 having two opposing primary cirmm, arepeatinginduction-coil whase seoondary circuit: is connected with bothsaid primary nircuits, and resistances for balancing the linen,substantially asset; forth.

5. In a telephonemepeater, the combination,

, with two teLaphoneJin-es, of'arecaiving inducfiiOIl-OOH having twnopposing primary. cirnmm, arepwfiing inflnction'aoii whas second- :zo mycircuit is nonnented with both midi mary circuits, and resismnceslocatedin shunts mound such opposing primam gr circuitn for baL ancing theiimes, substantially as set fmsfli.

This specification signed and wibnesnefl this 9th day of December,1884..

, THOS.- A EDISON.

Wibnesnm:

W lvlnmowwnom, 17mm G. GREENE}, Jr.

